<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <input type="button" id="btn" value="更换颜色" />
    <script>
        //1、绑定点击事件
        //2、随机生成一个RGB的颜色值
        //3、修改body标签的背景色(document.body.style.backgroundColor = 'rgb(1,1,1)')
    </script>
</body>
</html>